During the operation of packing machines (packaging lines) not infrequently events occur which require that the machine be brought to a stop. Such occurrences are:
(a) the lack of wrapping material caused by using up the wrapper reel or by a severance of the wrapper (paper) web;
(b) the lack of the bulk material to be packaged, caused, for example, by improper resupply; and
(c) the accumulation track (conveying lane) for removing or further processing the filled and closed packages is full, either because of a failure to remove the packages or a stoppage or slowdown of a machine wrapping the finished packages together to obtain collection boxes.
In the event of a defective operation of, for example, the above-outlined kind, the apparatus should be switched off to prevent further defects such as, for example, a soiling with adhesive in case no wrapping material is present or forwarding only partially filled or even empty bags in case of missing bulk material or the crowding of bags on the track of accumulation and damage thereto by the crushing effect of pressure forces or by falling off the overcrowded accumulation track.
It is known that when the packing machine resumes normal operation, at least some of the packages may be defective until the apparatus has passed a transient period. Such defective packages which have to be removed, result in loss of material and time. The stoppage of the machine itself, however, leads to disadvantages such as drying of the adhesive on the wrapper material, resulting in defective seals of the later-formed bags or such bags could accidentally open. Further, at the bag-forming station an escape of the adhesive may occur which subsequently has to be removed manually from mandrels or shaping boxes. It has been found that the machine could not be automatically restarted because, for example, pieces of the wrapper material between the paper-advancing rollers and bag-forming station have caused disturbances so that often maintenance personnel had to assume both the monitoring and the restarting which again has resulted in significant loss in labor and material.